In constant/chemistryProperties in addition to the specification of the initial
ODE integration time-step used at the start of the run:
initialChemicalTimeStep 1e-12;
this time step may now also be specified for every chemistry integration by
setting the optional entry maxChemicalTimeStep, e.g.
maxChemicalTimeStep 1e-12;
OpenFOAM can now be compiled with single, double or long double scalars by
setting the WM_PRECISION_OPTION environment variable to either SP, DP or LP
respectively.
On most 64bit systems long double is stored as 128bit but computed in the
floating point hardware to 80bit. Due to the increased storage compared to
double precision cache and memory access is significantly more time consuming
causing a slow-down of floating point intensive operations by a factor of 2 to
3.
and optionally the CPU and clock times per time step.
Example of function object specification:
time
{
type time;
libs ("libutilityFunctionObjects.so");
writeControl timeStep;
writeInterval 1;
perTimeStep no;
}
Adding
#includeFunc time
to the functions list in the controlDict of the motorBike tutorial generates
0 1.190000e+00 1
1 1.640000e+00 1
2 1.940000e+00 2
Enabling the optional writing of the CPU and clock time per time step is
straight forward:
#includeFunc time(perTimeStep=yes)
When etc/controlDict::writeJobInfo is set to 1 jobInfo.<pid> files are written
to the case directory containing a summary of the execution of the job containing
startDate
startTime
userName
foamVersion
code
argList
currentDir
PPID
PGID
foamBuild
root
case
nProcs
When the job completes the following additional entries are written:
cpuTime
endDate
endTime
termination
The original etc/controlDict::writeJobInfo control has been renamed writeJobControl and when set
to 1 writes the ~/OpenFOAM/jobControl/runningJobs and finishedJobs files for job control.
Specifying default fields for complex and multi-phase cases is simplified and
generalized by using wildcards to select sets of related field names, e.g.
defaultFields (p p_rgh U "U\..*" T "T\..*" "alpha\..*");
selects the velocity, temperature and phase-fraction fields of all phases in
addition to the pressure fields.
The default patch types specified in the new defaultPatchTypes entry of the
etc paraFoam configuration dictionaries:
defaultPatchTypes (patch wall);
Wildcards are supported, for example to specify that all patches loaded simply set
defaultPatchTypes to
defaultPatchTypes (".*");
The new default paraFoam configuration is in the files OpenFOAM-dev/etc/paraFoam
containing the entry
defaultFields (U p p_rgh T alpha.water alpha.air);
specifying the set of fields which are loaded by default if available. This
setting maybe overridden by providing additional paraFoam configuration files in
any of the OpenFOAM etc directories searched, listed using
foamEtcFile -list
e.g.
~/.OpenFOAM/dev
~/.OpenFOAM
~/OpenFOAM/site/dev
~/OpenFOAM/site
~/OpenFOAM/OpenFOAM-dev/etc
The new configurable set of default fields loaded replaces the original hard-coded default of
"p" and "U" and is much more convenient for current OpenFOAM usage.
ParaView has been updated to version 5.4.0. The C++ panel has been
deleted and replaced with a panel based on the new(er) XML API. This
reader works for ParaView-4.0.1 and newer. The ParaView 3 reader remains
unchanged.
Update issues have also been fixed. All the time directories are now
scanned for fields and clouds when filling the selection lists. This
stops fields from disappearing when the time is changed. The scan is
only done on startup and when the refresh button is pressed.
The list of available Lagrangian fields also now shows a combined set of
all the clouds. Previously, only fields from the first cloud were shown.
If a field does not apply to all the clouds, ParaView will display it's
name in the dropdown menu with a "(partial)" qualifier.
Some undocumented and incomplete bits of code, which were not being
compiled, have been removed.
When an OpenFOAM simulation runs in parallel, the data for decomposed fields and
mesh(es) has historically been stored in multiple files within separate
directories for each processor. Processor directories are named 'processorN',
where N is the processor number.
This commit introduces an alternative "collated" file format where the data for
each decomposed field (and mesh) is collated into a single file, which is
written and read on the master processor. The files are stored in a single
directory named 'processors'.
The new format produces significantly fewer files - one per field, instead of N
per field. For large parallel cases, this avoids the restriction on the number
of open files imposed by the operating system limits.
The file writing can be threaded allowing the simulation to continue running
while the data is being written to file. NFS (Network File System) is not
needed when using the the collated format and additionally, there is an option
to run without NFS with the original uncollated approach, known as
"masterUncollated".
The controls for the file handling are in the OptimisationSwitches of
etc/controlDict:
OptimisationSwitches
{
...
//- Parallel IO file handler
// uncollated (default), collated or masterUncollated
fileHandler uncollated;
//- collated: thread buffer size for queued file writes.
// If set to 0 or not sufficient for the file size threading is not used.
// Default: 2e9
maxThreadFileBufferSize 2e9;
//- masterUncollated: non-blocking buffer size.
// If the file exceeds this buffer size scheduled transfer is used.
// Default: 2e9
maxMasterFileBufferSize 2e9;
}
When using the collated file handling, memory is allocated for the data in the
thread. maxThreadFileBufferSize sets the maximum size of memory in bytes that
is allocated. If the data exceeds this size, the write does not use threading.
When using the masterUncollated file handling, non-blocking MPI communication
requires a sufficiently large memory buffer on the master node.
maxMasterFileBufferSize sets the maximum size in bytes of the buffer. If the
data exceeds this size, the system uses scheduled communication.
The installation defaults for the fileHandler choice, maxThreadFileBufferSize
and maxMasterFileBufferSize (set in etc/controlDict) can be over-ridden within
the case controlDict file, like other parameters. Additionally the fileHandler
can be set by:
- the "-fileHandler" command line argument;
- a FOAM_FILEHANDLER environment variable.
A foamFormatConvert utility allows users to convert files between the collated
and uncollated formats, e.g.
mpirun -np 2 foamFormatConvert -parallel -fileHandler uncollated
An example case demonstrating the file handling methods is provided in:
$FOAM_TUTORIALS/IO/fileHandling
The work was undertaken by Mattijs Janssens, in collaboration with Henry Weller.
"pos" now returns 1 if the argument is greater than 0, otherwise it returns 0.
This is consistent with the common mathematical definition of the "pos" function:
https://en.wikipedia.org/wiki/Sign_(mathematics)
However the previous implementation in which 1 was also returned for a 0
argument is useful in many situations so the "pos0" has been added which returns
1 if the argument is greater or equal to 0. Additionally the "neg0" has been
added which returns 1 if if the argument is less than or equal to 0.
In addition to local Doxygen HTML directories an optional HTTP server directory
may be specified:
Documentation
{
docBrowser "firefox";
doxyDocDirs
(
"$WM_PROJECT_USER_DIR/html"
"~OpenFOAM/html"
"$WM_PROJECT_DIR/doc/Doxygen/html"
"http://cpp.openfoam.org/dev"
);
doxySourceFileExt "_8C.html";
}
from which the Doxygen documentation files may be obtained so now the "-doc"
command-line option may be used even if if Doxygen has not been run locally,
e.g.
pimpleFoam -doc
When typing OpenFOAM commands, the bash completion system will
complete option names, e.g. -help, -parallel, etc. After typing an
option that includes an argument, e.g. -case <dir>, completion will
adjust to the type of argument, e.g. present directories if the
argument is a directory. Similarly, for applications with mandarory
file arguments, file (and directory) names will appear on the
completion list.
terms of the local barycentric coordinates of the current tetrahedron,
rather than the global coordinate system.
Barycentric tracking works on any mesh, irrespective of mesh quality.
Particles do not get "lost", and tracking does not require ad-hoc
"corrections" or "rescues" to function robustly, because the calculation
of particle-face intersections is unambiguous and reproducible, even at
small angles of incidence.
Each particle position is defined by topology (i.e. the decomposed tet
cell it is in) and geometry (i.e. where it is in the cell). No search
operations are needed on restart or reconstruct, unlike when particle
positions are stored in the global coordinate system.
The particle positions file now contains particles' local coordinates
and topology, rather than the global coordinates and cell. This change
to the output format is not backwards compatible. Existing cases with
Lagrangian data will not restart, but they will still run from time
zero without any modification. This change was necessary in order to
guarantee that the loaded particle is valid, and therefore
fundamentally prevent "loss" and "search-failure" type bugs (e.g.,
2517, 2442, 2286, 1836, 1461, 1341, 1097).
The tracking functions have also been converted to function in terms
of displacement, rather than end position. This helps remove floating
point error issues, particularly towards the end of a tracking step.
Wall bounded streamlines have been removed. The implementation proved
incompatible with the new tracking algorithm. ParaView has a surface
LIC plugin which provides equivalent, or better, functionality.
Additionally, bug report <https://bugs.openfoam.org/view.php?id=2517>
is resolved by this change.
except turbulence and lagrangian which will also be updated shortly.
For example in the nonNewtonianIcoFoam offsetCylinder tutorial the viscosity
model coefficients may be specified in the corresponding "<type>Coeffs"
sub-dictionary:
transportModel CrossPowerLaw;
CrossPowerLawCoeffs
{
nu0 [0 2 -1 0 0 0 0] 0.01;
nuInf [0 2 -1 0 0 0 0] 10;
m [0 0 1 0 0 0 0] 0.4;
n [0 0 0 0 0 0 0] 3;
}
BirdCarreauCoeffs
{
nu0 [0 2 -1 0 0 0 0] 1e-06;
nuInf [0 2 -1 0 0 0 0] 1e-06;
k [0 0 1 0 0 0 0] 0;
n [0 0 0 0 0 0 0] 1;
}
which allows a quick change between models, or using the simpler
transportModel CrossPowerLaw;
nu0 [0 2 -1 0 0 0 0] 0.01;
nuInf [0 2 -1 0 0 0 0] 10;
m [0 0 1 0 0 0 0] 0.4;
n [0 0 0 0 0 0 0] 3;
if quick switching between models is not required.
To support this more convenient parameter specification the inconsistent
specification of seedSampleSet in the streamLine and wallBoundedStreamLine
functionObjects had to be corrected from
// Seeding method.
seedSampleSet uniform; //cloud; //triSurfaceMeshPointSet;
uniformCoeffs
{
type uniform;
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
to the simpler
// Seeding method.
seedSampleSet
{
type uniform;
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
which also support the "<type>Coeffs" form
// Seeding method.
seedSampleSet
{
type uniform;
uniformCoeffs
{
axis x; //distance;
// Note: tracks slightly offset so as not to be on a face
start (-1.001 -0.05 0.0011);
end (-1.001 -0.05 1.0011);
nPoints 20;
}
}
by combining with and rationalizing functionality from
turbulentHeatFluxTemperatureFvPatchScalarField.
externalWallHeatFluxTemperatureFvPatchScalarField now replaces
turbulentHeatFluxTemperatureFvPatchScalarField which is no longer needed and has
been removed.
Description
This boundary condition applies a heat flux condition to temperature
on an external wall in one of three modes:
- fixed power: supply Q
- fixed heat flux: supply q
- fixed heat transfer coefficient: supply h and Ta
where:
\vartable
Q | Power [W]
q | Heat flux [W/m^2]
h | Heat transfer coefficient [W/m^2/K]
Ta | Ambient temperature [K]
\endvartable
For heat transfer coefficient mode optional thin thermal layer resistances
can be specified through thicknessLayers and kappaLayers entries.
The thermal conductivity \c kappa can either be retrieved from various
possible sources, as detailed in the class temperatureCoupledBase.
Usage
\table
Property | Description | Required | Default value
mode | 'power', 'flux' or 'coefficient' | yes |
Q | Power [W] | for mode 'power' |
q | Heat flux [W/m^2] | for mode 'flux' |
h | Heat transfer coefficient [W/m^2/K] | for mode 'coefficent' |
Ta | Ambient temperature [K] | for mode 'coefficient' |
thicknessLayers | Layer thicknesses [m] | no |
kappaLayers | Layer thermal conductivities [W/m/K] | no |
qr | Name of the radiative field | no | none
qrRelaxation | Relaxation factor for radiative field | no | 1
kappaMethod | Inherited from temperatureCoupledBase | inherited |
kappa | Inherited from temperatureCoupledBase | inherited |
\endtable
Example of the boundary condition specification:
\verbatim
<patchName>
{
type externalWallHeatFluxTemperature;
mode coefficient;
Ta uniform 300.0;
h uniform 10.0;
thicknessLayers (0.1 0.2 0.3 0.4);
kappaLayers (1 2 3 4);
kappaMethod fluidThermo;
value $internalField;
}
\endverbatim
